Nowadays several types of apparatuses are known for the towed connection of a children's bicycle to another, an adult's, bicycle.
A first type of such structures is provided with a contoured arm provided at a first end with a connector joined thereto by way of a universal joint.
The connector is adapted to be integrally coupled to the shank or to the head tube of the saddle of the towing bicycle.
When the connector is coupled to the towing bicycle, the universal joint enables, with respect thereto, the oscillation of the arm with respect to an axis that is substantially parallel to the ground and with respect to an axis that is substantially perpendicular to the ground.
At the second end, the arm is provided with an upward-curved lug which is provided, at the antinode, with pins with nuts for connection to the fork of the bicycle to be towed, replacing the corresponding wheel.
Moreover, at the free end tip of the lug, the arm is provided with a bracket for the integral coupling thereof with the lower tube of the frame of the bicycle to be towed.
Thus, the arm, when joined to both bicycles, towing and being towed, prevents both the rolling and the pitching of the towed bicycle with respect to the towing bicycle.
A drawback of this type of apparatus consists in that in order to join the two bicycles it is necessary to remove the front wheel of the bicycle to be towed, in order to couple the towing arm to the fork.
Not only is the operation for mounting and dismounting the front wheel complicated, but also, during use, the fact that the towed bicycle is deprived of its front wheel prevents the temporary use thereof once it is detached from the towing bicycle, unless the wheel is remounted.
Therefore, such an apparatus is extremely inconvenient for the parent who intends to accompany the child, by towing his or her bicycle, to a safe place where he or she can be allowed to freely use his or her bicycle.
In fact the parent would have to dismount the front wheel of the child's bicycle in order to connect the towing apparatus thereto and accompany the child to where he or she can use his or her bicycle, then re-mount the wheel and subsequently dismount it again for the return trip, with the added inconvenience that, during the towing, the dismounted front wheel must be brought along so that it can be re-mounted when needed.
An apparatus has been devised in order to avoid the dismounting of the front wheel of the bicycle to be towed, whose arm is provided at the two opposite ends with connectors to the head tubes of the saddles of the bicycles, towing and being towed, and, in an intermediate position on the arm, it is provided with a transverse secondary arm which juts out to be connected to the hub of the front wheel on one side thereof.
Such a structure, however, is cumbersome since, at the end thereof for connection to the bicycle to be towed, the main arm runs laterally to the frame thereof thus interfering with the legs of the cyclist who has mounted it.
A further apparatus which is described in detail in EP 0966383 comprises a telescopic towing arm provided at its two ends with corresponding connectors, one for the connection to the head tube of the saddle of the towing bicycle and one for the connection to the head tube of the steering column of the bicycle to be towed.
The connector between the towing arm and the head tube of the steering column of the bicycle to be towed consists in a flange and two U-shaped brackets with threaded ends.
The brackets are mounted on the head tube so that their threaded ends are inserted through the flange that is placed at the front of the head tube.
Shims are interposed between the head tube and the flange at either one bracket or the other, for adjusting the angle of inclination of the bracket, on which the height depends to which the front wheel of the bicycle to be towed is lifted, when it is fixed to the arm joined to the towing bicycle.
A drawback of this structure consists in the complexity of the prearrangement of the shims for adjusting the upward pitch of the bicycle to be towed, substantially as a function of the size thereof.